When done right, VR's ability to convey presence -- the feeling of actually being somewhere -- is unrivaled by any other medium. Nowhere is that more apparent than when you're craning your neck to take in the size of the zebra-striped brachiosaur lumbering through a tar pit in Crytek's Robinson: The Journey. Same goes for ducking under a bellowing tyrannosaur stomping through a museum hall in an Oculus tech demo. Some 65 million years later, developers love to resurrect nature's most fearsome creatures in VR. But why?